Jeff - this is straight from the WCPGA site:

DATE: JUNE 6, 2009 SAT.

TRACK: INFINEON RACEWAY, SONOMA, CALIF.

EVENT: A/GAS ASSOC. FEE $100.00 see below B/C/D GAS...ASSOC.FEE $50.00 .........see below ... add on with ET series

INFO:JUNE 7, 2009 SUMMIT SERIES SUN

The rest is pure speculation about how they would do it - I've never been to a Mopar race at Infineon before.